<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<script type="text/javascript">
			var arr = [1,4,6,8,2,34,62,81,54,2,13,11,12,67,89,78,75,35,98,92]
			
			var arr1 = arr.slice(0,10)
			arr1.sort(function(x,y){
				return x-y;
			});
			console.log(arr1);
			
			var arr2 = arr.slice(11,20);
			arr2.sort(function(x,y){
				return y-x;
			});
			console.log(arr2);
			
			var arr3= arr1.concat(arr2);
			console.log(arr3)
			
		</script>
	</head>
	<body>
	</body>
</html>
